Deciduous is a designation indicating a plant sheds its leaves at the end of the growing season. The term is used primarily in reference to trees and shrubs, in contrast with those that are evergreen.. It is pronounced dih-SIJ-oo-uhs. To remember what deciduous means, try relating it to the word, decadent..
viscosity. n, pl-ties. 1. the state or property of being viscous. 2. (General Physics) physics. a. the extent to which a fluid resists a tendency to flow. b. Also called: absolute viscosity a measure of this resistance, equal to the tangential stress on a liquid undergoing streamline flow divided by its velocity gradient. It is measured in newton seconds per metre squared.
Technically, viscosity is defined as resistance to flow. Commonly though, we think of it as an oil's thickness. To be more specific, it is the thickness of an oil at a given temperature. The plot thickens (ha!).The viscosity of an oil could be reported at any temperature, but to standardize things, most laboratories report either a low temp (100F or 40C) or a high temp (210F or 100C) and stick with either SUS or cSt.o matter what you call it, the number given simply defines the thickness of the oil at the standard high temperature. Straight Weight vs. Multi-Grade Engine oil can be either a straight weight or a multi-grade viscosity.